Typically a driver side airbag module is mounted within a motor vehicle's steering wheel. This is the same area which conventionally includes the horn switch. Accordingly, the resilient thermoplastic airbag module cover has also served to actuate a horn switch. One way in which this has been accomplished has been to mount a membrane type switch on the back or inner surface of the airbag module cover. Membrane type switches conventionally comprise two very thin sheets having conductive coatings which are normally separated by thin spacers. Pressure on the switch presses the conductive surfaces together to close a circuit and actuate the horn. The thickness of such a switch may be only, for example, approximately 0.25 mm thick.
Obviously in order to actuate a membrane switch, the force applied by the driver must be able to compress the switch. In prior art installations, the membrane switch could only be compressed against the folded airbag itself. As a result, a fairly substantial degree of cover depression was required. The result was less than optimum reliability and slowed reaction in emergency situations.
Accordingly, it a primary object of the present invention to provide an improved airbag cover and horn switch assembly having increased reliability and emergency actuation response. Other objects, features, and advantages will become apparent from the following description and appended claims.